U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL INDUSTRY.— Bulletin No. 66-' 
D. E. SALMON, D. V. M., Chief of Bureau. 



S F 

968 

Tv2Z 



THE GID PARASITE {CCENUBUS CEREBRALIS) 
ITS PRESENCE IN AMERICAN SHEEP. 



BY 



B. H. RANSOM, B. Sc, A. M., 

Scientific Assistant in Cliar^re of the Zoological Laboratory, 
Bureau of Animal Industry. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 
1905. 



^mnf^t^ 




Class. 
Book_ 



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U. S. DEPARTMENT OF AGRICULTURE, 

BUREAU OF ANIMAL 1 NDUSTRY.— Bulletin No. 66. 



D. E. SALMON, D. V. M., Chief of Bureau. 



^^ 



THE GID PARASITE {CCENURUS CEREBRALIS): 
ITS PRESENCE IN AMERICAN SHEEP. 



BY 



B. H. RANSOM, B. Sc, A. M., 

Scientific Assistant in C/iarge of the Zoological Laboratory , 
Bureau of Animal Industry. 




WASHINGTON : 

GOVERNMENT PRINTING OFFICE. 
1905. 



^ 






V 



''I'o?^,^ 



LETTER OF TRANSMIITAL 



U. S. Department of A(tRIculture, 

Bureau of Animal Industry, 

Sir: I have the honor to transmit herewith a manuscript entitled 
*'The Gid Parasite {Oinxrm cti^ebml/K): Its presence in American 
Sheep," by B. II. Ransom, B, Sc, A. M., scientific assistant in charge 
of the zoological laboratory of this Bureau. 

This parasite in its bladderworm stage ( C<ef> unis cerehr(fh'.'<) cnusen 
the disease called gid, otherwise known as "sturd}'," "staggers," etc., 
which principally affects sheep, although cattle and other herbivorous 
animals are also susceptible. It is transmitted to stock through pasture 
or water which has been contaminated b}' the eggs of a certain species 
of tapeworm {Txnla camurus) parasitic in the intestines of dogs, the lat- 
ter having acquired the parasite by feeding upon the carcasses of stock 
infested with the bladderworm stage. Although a common disease 
in Europe, where it frequently- occasions losses of fully 10 per cent 
in flocks of sheep, gid has until veiy recently been unknown in the 
United States. Early in the present year, however, a well-authen- 
ticated outbreak occurred in the sheep-grazing regions of the West, 
and it was, consequently, deemed expedient to publish such facts as 
would help our stockmen to protect themselves against possible out- 
breaks in the future. 

The information concerning gid herein set forth is of nuich practical 
importance to sheepmen, as it enables them to recognize the disease 
should it make its appearance, and indicates the measures best calcu- 
lated to prevent its spread. I therefore recommend that the work be 
published as Bulletin No. 6«> of the series of this Bureau. 
Respectfullj% 

D. E. Salmon, Chief of Bureau. 

Hon. James Wilson, 

Secretary of Agriculture. 



C N T 1: X T S . 



Page. 

Introduction 7 

Presence of gid in the United Staten 8 

Historical review of gid 8 

Economic importance of gid *) 

Description of the gid l)ladderworm ( Cotnurus ceri'hralis) 10 

Description of the gid tapeworm ( Tamia cmmrm) 12 

Life history of the gid parasite 14 

SusceptibiHty of sheep and other animals '. 16 

Symptoms — 

Cephalic gid 1 «} 

Medullary gid 17 

Pathology 17 

Diagnosis 20 

Treatment 20 

Prevention 20 



USTRATIONS. 



Page. 

Fig. 1. Gid bladderworm ( Crenurn^ cereliralts), showing the heads 10 

2. Diagrammatic section of a gid bladderworm 11 

3. Larval tapeworm head dissected away from the wall of a gid bladder- 

worm 11 

4. Hooks from the gid bladderworm 12 

5. Hooks from a l)la(lderworm of the rabbit ( C(r)i;nrtis serlali.^) 12 

fi. Portions of an adult gid tapeworm ( Tirnla ca'nnrns) 13 

7. Sexually mature segment of the gid tapeworm 13 

S. Gravid segments of tapeworms of dogs, showing the median stem of 

the uterus and its lateral Ijranches 14 

9. Gravid segment of Ts-n'ia serialis, a tapeworm (if dogs often confused 

with T. cfenums 15 

10. Brain of lamb showing the furrows produced by the migration of 

young gid bladderworms 15 

11. Skull of a sheep showing the brain infested with a gid bladderworm. . 18 

12. Sheep's skull, showing perforations resulting from the jiresence of gid 

blad«lerworms U) 

5 



THE GID PARASITE (C(ENURUS CEREBRALIS): 
ITS PRESENCE IN AMERICAN SHEEP. 

By B. H. Ransom, B. Sc, A. M., 
Scientific Assistant in Charge of Zoological Laboratory, Bureau of Animal Industry. 

INTRODUCTION. 

The disease popularl}" known by English-speakino- peoples as gid, 
sturd}^ staggers, turnsick, etc., which affects sheep, and, more rarely, 
cattle and other animals is a common disease of stock in Europe. It 
is said to occur also in South America, and is now known to occur in 
this country. The cause of this disease, a characteristic sj'mptom of 
which is vertigo and turning of the affected animal, is the presence of 
a parasite, the gid bladderworm (tig. 1), in the brain or spinal canal. 

The gid bladderworm, or Cmiurns cet'ebralis as it is known technic- 
ally, is the larval stage of a tapeworm, Tivnia C(enuri(i< (tig. 6), which is 
found in the intestines of dogs. When the brain of a "gidd}'" sheep 
is eaten by a dog, the bladderworm develops into tapeworms in the 
intestines of the latter. The tapeworms produce eggs, which pass out 
of the dog's intestines and fall to the ground, where they maj' lie amid 
the grass or be washed by rains into pools of water. Sheep and cattle 
while grazing or drinking ai"e liable to swallow these eggs, which 
tiien hatch out, and the embr3^os, boring out of the intestines, wander 
to the brain or spinal cord, where they undergo further development 
and give rise to the condition known as gid. 

It seems reasonable to suppose, in view of the large numbers of sheep 
and dogs which have been imported into the United States from coun- 
tries where gid is common, that the disease should have become more 
or less prevalent here also, but for some reason the gid parasite has 
never gained a foothold in North America, and until veiy recently, so 
far as it has been possible to determine, gid has been entirely unknown 
in this countiy. A possible exception ma}- V)e based on the mention 
made by Leidy (1856) of '"''Co&nurus cerebraUs Rud. in the sheep, 6'(2j>r« 
artes^'^ but neither the time nor the place of the collection of the 
specimens referred to l)v that author is known. Although heretofore 
no cases of gid in this country have been placed on record, it seems 
hardly probable, in view of our present knowledge, that the disease 

7 



8 BUREAU OF ANIMAL INDUSTRY. 

has been altogether absent. jSIore likely, oases have occurred from 
time to time and passed unrecognized, as evidence has come to hand 
which shows that the disease is now present in the United States, cases 
having developed recently which, as the attendant circumstances show, 
must have resulted from infection in this country. 

PRESENCE OF GID IN THE UNITED STATES. 

A number of native sheep died at Bozeman, Mont., in Januarj-, 
1904, with the characteristic symptoms of gid. These sheep were 
brought to the notice of officials of the Montana Agricultural 
College. On postmortem examination, bladderworms were found 
in the brain, and through the courtesy of Professor Cooley two 
specimens (B. A. I. Collection, No. .3644, figs. 3, 4) have been placed 
at the disposal of this laboi'atory. These specimens agree in all essen- 
tials with the European Ooenurus cerebralu^ so far as may be deter- 
mined from published descriptions of the latter, no specimens for 
comparison being at present available. The salient characteristics of 
the American form are as follows: Each specimen is nearl}- spherical, 
with a diameter of about 2.5 nmi. (about 1 inch). There are no sec- 
ondary or daughter bladders, either internally or externall}. The 
wall of the bladder consists of a thin semitransparent membrane, and 
its surface is marked by several groups of little white spots, the 
invaginated heads, or scolices, of the larval tapeworms, which num- 
ber over a hundred in each specimen. Each head is supplied with a 
double crown of 30 to 3:^ hooks, of two sizes, arranged alternately 
(figs. 3, 4). The larger hooks measure 160 to 170/< (y^g to y|o inch), 
and the smaller hooks 114 to 130/^ (^^^ to ylg inch) in length. In the 
latter the ventral root is slightly bifid. 

Although at present the gid parasite may be causing but little dam- 
age in the United States, the fact should be remembered that its history 
in other countries has shown it to be one of the most dangerous para- 
sites to Avhich sheep are subject, and the possibilit}' kept in view that 
it ma}' in the future become more widespread and prevalent in this 
countr}', and that, in this event, serious losses are liable to occur. 
Stock raisers, veterinarians, and all persons interested in live stock, 
especially sheep, should therefore be on their guard against the gid 
parasite, and, by taking proper preventive precautions — to be dis- 
cussed later — avoid in this country a possible repetition of the disas- 
trous experience of stock raisers abroad. 

HISTOKICAL REVIEW OF GID. 

Gid has been known for nearly three hundred years, and possibly 
longer, it having been traced in literature as far back as 1634. 
In that year a European surgeon named iieutten observed a sheep 



THE GID PARASITE IN AMERICAN SHEEP. 9 

affected with vertigo, and another surgeon, Scultetus, on making a 
postmortem examination of the animal, discovered in the brain a 
vesicle tilled with a limpid fluid. After this date the disease and the 
vesicle in the brain with which it is associated were noted b}' various 
authors, who attempted to explain in various ways the cause of the 
disease and advanced numerous theories to account for the presence 
of the vesicle. Methods of operation for the removal of the vesicle 
were also described, but not until the latter part of the eighteenth 
centur}'^ was the true njiture of the water}' vesicle in the brain of 
"giddy" sheep and cattle pointed out. In 1780 Leske demonstrated 
the animal nature of the vesicle by the discovery of tapeworm heads 
attached to its surface. Many years later another step was accom- 
plished in solving the question of the etiology of gid when Siebold 
(1852) discovered that if the gid bladderworm is fed to a dog it devel- 
ops into mature tapeworms in the intestines of the latter. The fol- 
lowing 3'ear Kiichenmeister (1853) showed further that the eggs from 
tapeworms thus produced in dogs, when fed to sheep, develop into 
bladderworms in the brain. Since that time the experiments of Sie- 
bold and Kiichenmeister have been many times repeated, and the 
relation between Coenurus cerebralis in the brain of sheep and other 
animals and Taenia coenurus in the intestines of dogs, as larval and 
adult stages, respectively, in the life history of a single species of para- 
site, has been most firmly established. 

ECONOMIC IMPORTANCE OF GID. 

Gid was soon recognized in Europe, after its first discover}^ as one 
of the most important diseases of sheep; large numbers of animals 
were lost annually from this cause, and at times in some localities the 
flocks were almost annihilated. 

The following quotations from the literature on the subject will 
serve to indicate the important nature of the disease, and will give 
some idea of the damage which has been caused by the gid parasite in 
countries w here it has been prevalent. It will be noticed that most of 
the authors quoted refer to conditions which existed before the life 
history of the parasite was known and before the proper means for 
its prevention were recognized. The percentages given will, in gen- 
eral, probably not apply at the present time, as many stock raisers of 
Europe have long since realized the practical value of preventive 
measures, and this has resulted in a material reduction of the general 
mortality from gid, although in isolated cases where proper precau- 
tions are neglected the former high percentage of mortality is still the 
rule. 

Wepfer (about 1659) reported an epizootic of the disease which 
occurred in the year 1650 among cattle in a certain locality of Ger- 
man}'. In 1752 there were great losses from gid among both sheep 
11896— No. 66—05 2 



10 BUREAU OF ANIMAL INDUSTRY. 

and cattle in Iceland, Sooner or later the disease attracted attention 
in almost every country in Europe. 

Tessier (? 1810), according- to Numan (1850), placed the annual loss of 
sheep from gid in France at about 5 percent. Kuers (1810) estimated 
the loss in Germany at about the same figure, and Fricke (1811) stated 
that in his own flocks the losses at one time reached as high as 10 per 
(Cent. Numan (1850) states that, while the disease is well known in 
Holland, it is not so common as in some other countries, although at 
times it assumes the character of an epizootic. He further states that 
in some parts of Germany and Austria the loss is 10 per cent, and that 
in many localities the sheep industry has declined serioush' in con- 
sequence. 

Fleming (in Neumann, 1892) quotes a statement of Youatt that in 
France 1,000,000 sheep die annually from gid, and states that Gasparin 
has put the losses in Germany at 15 per 1,000 in the first year of life, 
5 in the second year, 2 in the third 3'ear, and 1 in the fourth. In 

England, where the disease is more or less 
prevalent, the number of sheep lost in some 
flocks has reached as high as 35 per cent 
(Veterinarian, 1871, p. 547). 

Armatage (1895) estimates the annual losses 
in Great Britain at about 10 per cent, and 
states that gid "always prevails in some dis- 
tricts, particularly in Scotland, and upon all 
uninclosed lands where sheep are gathered 
Fig. 1— Gid biadderworm [Coenu- in large flocks and attended by dogs." 
rus cereb,-aus), showing the ^^ ^^ illustration of the extent to which 

heads, each one of which repre- 
sents an immature tapeworm, a single flock ma}'^ be invaded bv gid, an 

m6T2Tf^s.mT ""''"'''' instance observed by Brunet (1875) in the 

Bas Berry region, France, may be referred 
to. In this case over 80 sheep in a flock of 212, or about 10 per cent, 
were affected. 

DESCRIPTION OF THE GID BLADDERWORM (COENURUS CEREBRALIS). 

(Figs. 1-4, 10-12.) 

Coenurus cerehmlis, the larval stage of the gid parasite, is most fre- 
quent!}^ found in the brain of sheep and more rarely in the spinal cord. 
It has also been found in other herbivorous animals — ox, goat, reindeer, 
roedeer, antelope, dromedary, and horse. No authentic case of C'a'nu- 
7nis cerebralis in man has been recorded. A number of isolated cases 
are on record in which bladderworms VQi^emhWng Ovnu rus certhralis, 
and probably identical with it, have been found in locations other 
than the brain. Eichler and Nathusius have reported such bladder- 
worms in the subcutaneous tis.sue of sheep, and Heincke (1882) has 




THE GID PARASITE IN AMERICAN SHEEP. 



11 



rocorded the present'e of a ODnirus in the C3'e of ii horse. Kabe (1889) 
discovered in the brain, muscles, lymphatic glands, and thyroid body 




>4 



Fig. 2. — Diagrammatic section of a gid bladderworm {Ccenurus ccnbraiis): a. normal disposition of 
scolcx; b, c, d, c, diagrammatic representation to show the homol >gy between cysticercus and 
coenunis. (After Railliet, 1886, p. 243, fig. 134.) 

of an antelope specimens of a bladderworm which he identified as 
Canurus cerehralis. In general, however, C<jenurus cerebralis fails to 
develop in an}^ other location 
than the central nervous sys- 
tem, and the embr3'os which 
do not succeed in reaching 
the brain or spinal cord soon 
degenerate. 

The bladderworm (figs. 1, 2) 
consists of a membranous 
vesicle, the wall of which 
bears numerous small invagi- 
nations resembling tapeworm 
heads (fig. 3), each one of 
which, when swallowed b}^ a 
dog, is capable of transform- 
ing into an adult tapeworm, 
Taenia cmua'us. In its growth 
the vesicle tends to assume a 
spherical form and attains a 
size varying from that of a 
hazelnut to that of a hen's 
eg^. The form of the bladder 
is modified according to its location 
canal it becomes much elongated. 




Fig. 3.— Larval tapeworm head dissected away from 
the wall of a gid bladderworm (Ccenurus cerebralis). 
X 38. (Original drawing, specimen No. 3644, B. A. I. 
Helminthological Collection.) 



When situated in the spinal 
The wall of the bladder is very 



12 



BUREAU OF ANIMAL INDUSTRY. 



thin, translucid, and contains contractile fibers. It is filled with a 
colorless, watery fluid containing- 1 to 2 per cent of animal matter 
and less than 1 per cent of inorganic salts. The heads of the larval 
tapeworms, which appear as little white spots arranged in irregular 
groups and usually confined to one region of the vesicle, probably cor- 
responding to the posterior part of the eniibryo, may number more 
than 500 in a single specimen, but usually they are not so numerous. 
They are general]}' found invaginated and project into the interior of 
the vesicle; but Davaine (1858) has observed that the}- are capable of 

evagination, and thus become an active source of 

irritation to the brain. Not all 

of the heads are found equally 

developed. Some of them can 

not ])e distinguished from the 

head of the adult, while others 

are rudimentar3\ 

The hooks, suckers, and other 

details of the head are similar 

in the larva and in the adult, 

and will be described in con- 
nection with the description of 

the latter. 

DESCRIPTION OF THE GID TAPE- 
WORM (t^nia ccenurus). 

( Figs. 6-8, see also figs. 3-5, 9. ) 

Tsenia ccenurus^ the adult 

stage of the gid parasite, is 

found in the intestines of dogs, 

and is said to occur also in foxes, 

and probably also in wolves. 

It is not known to occur in other animals. Another 

tapeworm of the dog, Tsenia seivalts^ is often mistaken for it. 

pare figs. 4, 5, 8 6; 9.) 

Omitting an extensive discussion of the anatomy of the worm, the 
essential characteristics of Tsenia cmnurus are as follows: 

The average length is 10 to 60 cm. (16 to 21 inches) and the maxi- 
mum 1 meter (10 inches). It possesses a head, or scolex, an unseg- 
mented neck, and a long segmented portion consisting of two hun- 
dred to two hundred and fifty segments, or proglottids (fig. 6). 

The fully developed head is pyriform and measures about 0.8 mm. 
(aV inch) in diameter. It is supplied with four suckers, 0.30 mm. 
(sV inch) in diameter, and a rostellum, also about 0.30 mm. in diame- 
ter, bearing a double crown of 22 to 32 hooks (fig. 1) of two kinds, 
large and small, arranged alternately. The suckers and rostellum 





Fig. 4. — Hooks from the 
gid bladderworm (Cte- 
nurus cerebraUs) . X 240. 
(Original drawing, 
specimen No. 3644, B. 
A. I. Helminthological 
Collection.) 



Fig. 5.— Hooks from a 
bladderworm of the 
rabbit ( Qvnums serialis, 
the larval stage of a 
tapeworm of the dog, 
Tienia serialis). X 240. 
(Original drawing,spec- 
imeu No". 1823, B. A. I. 
Helminthological Col- 
lection.) 



(Com- 



THE GID PARASITE IN AMERICAN SHEEP. 



13 



serve to attach the worm to the intestinal wall of its host. The large 
hooks measure 150 to ITOyu (j^j to -^^^ inch) and the small hooks 90 
to 130yw (^io to yis inch) in length. 

The neck is slender and 2 to 3 mm. (jV to ^ inch) long. In the region 
of the neck the segments (tig. 6) are very short and narrow, but 
toward the posterior end of the worm 
they gradually increase in size. The 
last twelve to fifteen segments are 
much longer than broad, in form 
somewhat resembling cucumber 
seeds, and measure 8 to 9 mm. (about 
I inch) long by 3 to 5 mm. (i to | 
inch) broad. Near the middle of the 
right or left lateral margin of each 
segment is a small opening — the 
genital pore. 

During the life of the worm new 





Fig. 6.— Portions of an adult gid tapeworm 
[Tmnia coeiiurus). Natural size. (After 
Railliet, 1893, fig. 146, p. 2.i2.) 

segments are continuallv being 

added in the neck region liy a 

process of intercalation. The 

FIG. 7.-^exuaiiy mature segment of the gid tape- Segments when first formed are 

worm ( Txnia ccenurus) showing: cjh cirrus pouch; gmall and SCXUall V Undeveloped. 

jrp,genital pore; 71, nerve; o!', ovary; Si?, shell gland; /^ i 1 1 i "^ .i 

<, testicles; <r, transverse canal; «^ uterus; )', vagina; LrraClUally, nO\\ e^ Cr, tUey are 

vc, ventral canal; vd, vas deferens; vg, yolk gland, pushed backward b V Still 

X 20. (After DefEke, 1891, pi. 1, fig. 3.) '■ ^ i • i * i i 

younger .segments which develop 
in front of them. They grow larger in all dimensions, and the 
sexual organs dev^elop (fig. T), reach maturity, and produce eggs, 
which are stored up by thousands in the uterus of each segment. 
Finally the gravid segments break away from the end of the chain and 
pass out of the dog's intestine. It results from this manner of growth 
that the small segments farthest anterior are the youngest, and the 



14 



BUREAU OF ANIMAL INDUSTRY. 



large hindermost segments are the oldest; thus, in a single worm, seg- 
ments in all stages of development may be found. 

The most conspicuous structure in the posterior segments (tig. 8 C) 
is the uterus tilled with yellowish or brownish eggs. The gravid 
uterus has a median stem with eighteen to twenty-six lateral branches 




Fig. 8. — Gravid segments of tapeworms of dogs, showing the median stem of the uterus and Its lateral 
branches. (A) Txnia serrata, X 4; {B) T. manjinata, X 6; (C) T. coenurus, X 10-15. (After Leuckart, 
1880, p. 720, fig. 308.) 

on each side. The latter are almost parallel to each other, and are 
unbranched or only slightly branched. 

The eggs, found in the gravid uterus, contain embryos with six 
hooks and measure from 31 to 36 yw (about ^^^o^ inch) in diameter. 

LIFE HISTORY OF THE GID PARASITE. 

As already stated, the gid bladderworm, Ctemirus cerebralis^ and 
the tapeworm, Tsenia coenurus^ are intimately related, the former 
being the larval stage of the latter. 

In detail the life history is as follows: A dog infected with Taenia 
canurus scatters the eggs and gravid segments of the tapeworm over 
the ground. Those eggs which fall into moist places may live for 
several weeks, but those exposed to hot, dry weather preserve their 
vitality only a few days at most. Sheep and cattle while grazing or 
drinking are liable to swallow some of the eggs thus spread broadcast 
by the infested dog. By the action of the digestive juices the shells 
of the eggs are dissolved and the embrj^os contained set free. The 
embryos then bore out of the intestine by means of their hooks and 
wander among the tissues. This migration is undoubtedly aided by 
the blood current in vessels penetrated by the embryos, which are 
thus carried passively to various parts of the body. Normally only 
those embryos which reach the central nervous sj'stem continue their 
development. Others failing to reach this location may live for a 
while, but generally die and soon disappear. After reaching the 



THE OID PARASITE IN AMERICAN SHEEP. 



15 



brain or spinal cord, which may occur within eight days after infection, 
the embryo loses its hooks and transforms into a small cyst. The 
3^oung ccBnurus preserves its power of locomotion for some time and 
may burrow along the surface of the 
brain, leaving a shallow, sinuous furrow 
(fig. 10) in its wake, but within a few 
days it becomes stationary. These furrows 
are to be found fourteen to thirty-eight 
davs after infestation; near the termi- 
nation of each is a small vesicle, the young 
gid bladderworm. As determined exper- 
imentally by Baillet, the vesicle, two or 
three wrecks after infestation, has attained 
a diameter varving from 0.6 to 3 mm. (jV 
to ^ inch); on the twenty-fourth day it is 
as large as a pea, but the w^all still re- 
mains thin and transparent. The heads 
begin to appear by the thirty-eighth day, 
when the vesicle has reached the size of 
a cherry, but they do not seem to attain 
their full development before the end of 
two or three months. The vesicle, how- 
ever, continues to grow, and new heads 
are in continuous process of formation, 
so that in addition to fully formed heads, 
very rudimentary heads and intermediate 
stages between the two are likely to be 
found on the surface of the same bladder. 

When a brain containing a bladderworm is eaten by a dog, the wall 
of the vesicle is digested, but the heads remain uninjured by the 
digestive juices and attach themselves to the wall of the intestine and 




Fig. 9— Gravid "egment of Taenia seri- 
alis, a tapeworm of dogs often con- 
fused with T.ctt'/iin-KS. X14. (Original 
drawing, specimen No. 2839, B. A. I. 
Helminthologieal Collection.) 




Fig. 10. — Brain of lamb showing the furrows produced by the migration of young gid bladderworms, 
taken at a time immediately following the period of invasion— i. e., from fourteen to thirty-eight 
days after infestation. Natural size. (After Leuckart, 1879, fig. 81, p. 173.) 

develop into the adult tapeworm. In one to two months the posterior 
segments of the worm become gravid with eggs, and breaking away 
from the rest of the chain begin to pass from the dog's intestine. 



16 BUREAU OF ANIMAL INDUSTRY. 

SUSCEPTIBILITY OF SHEEP AND OTHER ANIMALS. 

Gid is exceptional in sheep over two years old, the great majorit}^ 
of animals "which present symptoms of the disease being lambs and 
yearlings. The disease is more rare among cattle and goats, and still 
more rare in other animals. Cattle seem to be susceptible for a 
longer period than sheep, and although gid is more frequent in calves 
and yearlings, animals as old as five or six years are still subject to 
infestation. 

Certain breeds of sheep seem to be more susceptible than others, 
and in some cases this has been explained by the fact that some breeds 
graze closer to the ground and thus are more liable to take in tape- 
worm eggs and segments than others. The greater susceptibility of 
young animals has not been fully explained, but it has been supposed 
that the embrj^os of the worm are unable to penetrate the tinner 
tissues of adult animals, and consecpiently do not reach the brain. 

SYMPTOMS. 

The following account of the s3^mptoms of gid is based mainly on 
the description of the disease in sheep, given by Neumann (1892). 
The symptoms in cattle and other animals are of the same general 
character as those in sheep, showing minor ditferences probably in 
correspondence with the different natures of the animals affected. The 
t3'pe of S3"mptoms varies according as the bladder worm is located in 
the brain or spinal cord. If the parasite is located in the brain it 
gives rise to cephalic gid; if in the spinal canal, to raechillary gid. 

Ceijludlc gid.- — Unless the infestation is very heavy no symptoms are 
likel}" to appear during the stage of invasion of the parasites, or they 
ma}' be slight and pass unnoticed. When early symptoms occur the}' 
appear generally in the second or third week following infestation. The 
affected animal shows signs of congestion of the brain, there is indif- 
ference and weakness, the head is of unusually high temperature and 
is held in an abnormal position, and the eyes arc inflamed. Peculiar 
actions ma}' become evident. 

Frequently the animal turns in circles, or wheels about in one spot 
as on a pivot. In some cases it staggers about as though intoxicated, 
stumbles, and often falls. The eyes are turned in or out, there is 
grinding of the teeth, and sometimes convulsions. The animals may 
die in a few days in severe cases, but generally the symptoms disap- 
pear in eight or ten days, and a period of apparent recovery follows, 
corresponding to the period of growth of the parasite. In about 2 per 
cent of animals attacked the parasites apparently die, as no later symp- 
toms develop, but in the vast majority of cases, at the end of four to 
«ix months, symptoms appear which mark the final stage of the dis- 
ease, leading almost invariably to a fatal termination within a few 



THE GID PARASITE IN AMERICAN SHEEP. 17 

weeks at most. Usually these symptoms are the first to be noticed, as 
the initial symptoms are generally so slight that they pass nniveog- 
nizecl. Prior to the onset of the tinal symptoms and during- the growth 
of the parasite certain slight signs of an abnormal condition of the 
brain will be noticed from time to time by the careful observer, espe- 
cially in stormy weather. The time at which the symptoms of the 
tinal stage of the disease appear varies somewhat and according to the 
time at which infestation occurred, but it is generallv toward the end of 
winter or in the spring. The symptoms at this stage may be consid- 
ered as due in part to the pressure of the cfjenurus bladder on the 
brain, and in part to the active irritation produced by the larval tape- 
worm heads which are capable of being thrust out from the surface 
of the bladder. The symptoms vary according to the region of the 
brain occupied by the parasite. 

Generally, however, the affected sheep holds his head in an unusual 
position, his eyes are fixed, with dilated pupils, and he pushes against 
obstructions. He becomes feeble, loses his appetite, and lags behind 
the flock. He moves in circles which gradually become smaller and 
smaller until he turns as on a pivot, and he usually turns toward the 
side on which the brain is compressed. If the parasite is located in 
the anterior part of the brain, the sheep is likely to move straight 
forward, holding his head down and lifting his feet high. A great 
variety of other movements ma}^ be executed, the type of movements 
depending upon the locality of the brain affected. A characteristic 
of all these peculiar actions is their automatic and intermittent nature. 
They recur several times during the day, and ma}^ continue to apjjear 
during a period of four to six weeks, at the end of which the animal 
dies from paral^ysis or exhaustion. 

Medullary gid. — When the gid parasite is located in the spinal cord 
it generally occurs in the lumbar region, and the disease is then termed 
lumbar gid, or hydatic paraplegia. 

The chief symptom of lumbar gid is the gradually increasing weak- 
ness and paralysis of the hind quarters. The bladder and rectum 
become paralyzed, the wool is shed, and the animal becomes progres- 
sively thirmer, although he may retain his appetite and eat enormousl}^ 
This condition may persist for several months before death occurs 
from general debility and exhaustion. 

PATHOLOGY. 

(Figs. 10-12.) 

Neumann (1892) gives the following account of pathological lesions 
occurring in gid: 

Pathological anatomy. — At the autopsy of animals which have died of gid one or 
more Coenures are found in the cranium, as much more developed as the disease has 
been prolonged. When speaking of its etiology, and of the experiments which have 



18 



BUREAU OF ANIMAL INDUSTRY 



established this, the developmental phases of the parasitic vesicle were described. 
In practice, the number of Ccenures is generally limited, though Huzard has counted 
more than thirty in the head of a land). Their size and development are generally 
in inverse proportion to their number. Huzard has seen some which occupied nearly 
one-half of the cranial cavity. 

These vesicles are found at various parts of the brain. When they are small and 
deeply situated they are surrounded l)y a pseudopurulent exudate, which is yellow 
and creamy in places. If the Coenurus is voluminous the brain substance in its 




Fig. 11. — Skull of a sheep shoving the brain infested with a gid bladderworm {Ccenurus rnrhra/i-i), 
two-thirds natural size, (.\fter Railliet, 1886, p. 244, tig. 135.) 

vicinity is depressed, atrophied, wasted, and forms a more or less regular pouch, the 
wall of which is formed of flexuous, interrupted, or l)roken nerve tubes that are less 
numerous than in the normal substance; by nerve cells which are no longer in com- 
munication with the nerve tubes; by a large quantity of amorphous substance and 
molecular granules; and lastly, by calcareous crystalline particles. Capillary vessels 
traverse this layer, and are continuous with those of the cerebral substance ( Robin, 
quoted by Reynal). This pouch contains a grumous purulent matter, and the 
peripheral cerebral substance is inflamed, dense, and granular. 



THE GID PARASITE IN AMERICAN SHEEP 



19 



When the Ctenurus is in a ventricle, the roof of this is thinned and sometimes 
reduced to its envelopes; the septum lucidum, posterior pillar of the fornix and the 
corpus callosum are also thinned, and even perforated, and pushed toward the hemi- 
sphere or into the opposite ventricle, into which the vesicle sometimes protruih's. 

The old and voluminous Cd-nures, situated on the superficial parts of the l)rain, 
have, by compression, caused absorption and attenuation of the roof of the cranium, 
which yields to pressure of the fingers (fig. 12). 

In medullary gid the Ctenurus is elongated, fusiform, and from 3 to 5 cm., and 
even a foot long (Numan) . Usually there is only one and it is lodged in the lumbar 
region;, it may, however, occupy the cervical region (May), or the posterior j)art of 
the medulla oblongata (St()ring). In some cases it has undergone calcareous degen- 
eration and is only recognizable by its hooks, which have persisted ( Roll ). It some- 
times only occupies oiie-half of the spinal cord, sometimes the two divisions, or it is 




Fig. 12.— Sheep'3 skull, showing perforations resulting from the presence of gid bladderwornis. 
(After Dewitz, 1892, p. 65, fig. 47.) 

intermediate, and completely separates them ( Yvart). It may be situated deeply or 
only l^e beneath the arachnoid. The medullary substance is atrophied and hyper- 
emic where it is located or it is softened. The muscles of the hind quarters are 
wasted and otherwise show the alterations of cachexia. 

In a large numberof animals there are found in various organs — and especially the 
heart, lungs, liver, spleen, mesentery, and muscles — some round or ovoid greenish 
corpuscles from 1 mm. to 4 mm. in diameter. They are composed of an enveloping 
membrane and granular contents rich in fat globules. These are atrophied and 
degenerated Cu-nures, the remains of erratic embryos which have not met with the 
conditions favoral)le for their development. Nathusius and p]ichler have seen some- 
what large Co-nures in the subcutaneous connective tissue of the calf and sheep. 

The malady having generally a chronic course there are observed more or less 
everywhere the lesions of pronounced cachexia. 



20 BUREAU OF ANIMAL INDUSTRY. 

DIAGNOSIS. 

In diagnosing gid care should be taken not to confuse it with vertigo 
due to heat, epilepsy, blindness, false gid due to grul)s in the nasal 
cavities, and inflammation of the intracranial sinuses. Likewise, 
medullary gid should not be confounded with the trembling disease 
(Scotch louping-ill) or lumbar prurigo. 

In some respects the symptoms of gid present many similarities to 
those of the so-called loco disease of the Western States, and it does 
not seem unlikely that in some cases the two diseases have been con- 
fused. The latter disease, however, is more chronic in its course and 
does not present the acute symptoms of gid. It is also likely to 
become evident in animals too young to allow of sufiicient time for 
the development of symptoms of gid, except in cases where early symp- 
toms occur corresponding to the stage of invasion of the parasite. 
Loco disease, moreover, rarely seems to be a direct cause of death, and 
the condition of "loco" when once established persists indefinitely. 

When gid is suspected in a flock the be^t means for a positive diag- 
nosis consists in killing one of the aflected animals and examining the 
brain and spinal canal for the presence of the bladderworm. 

TRKATMENT. 

Treatment of gid with drugs is useless, and, on account of the loca- 
tion of the parasite, the various methods of operation which have been 
practiced are also of little practical use. Trephining and removing 
the parasite, cauterizing, several days refrigeration of the cranium 
wuth ice, or continuous irrigation of the skull with cold water for a 
period of two weeks, has resulted in a cure in some cases. An oper- 
ation may be attempted in the case of an especially valuable animal, 
but in general the surest econom}' is the slaughter of the animals as 
soon as sj'mptoms become evident. In case the disease is recognized 
during the period of invasion the animals may be fattened and killed 
])efore the flnal stage of the disease begins or immediately upon the 
appearance of the final symptoms. 

PREVENTION. 

Prevention of gid is, comparative!}^ speaking, a simple matter. With 
our complete knowledge of the life history- of the gid parasite, it is 
possible to prescribe certain rules which, if observed, will efli'ectually 
prevent the occurrence and spread of the disease. 

All superfluous dogs should be killed. It is hardly necessar}' to 
insist upon the destruction of wolves and foxes, on account of the 
possibility of infestation from this source, since they are alread}^ suffi- 
cientl}" under the ban for other reasons. A certain number of dogs 
are, of course, indispensable, and these animals should be treated sys- 



THE GID PARASITE IN AMERICAN SHEEP. 21 

tematictilly iit intervals for tapewoniLs. While the dog- is underuoiiro- 
treatment he should be kept tied up and all feces collected and l)urned 
or buried in quicklime. Prior to the administration of the vermifuge, 
a laxative, such as castor oil, should be given to empty the ))owels, and 
the animal then starved or fed on milk or soup until the following day. 

In giving fluid medicine to a dog the cheek should be pulled away 
from the teeth at the angle of the mouth, the medicine poured into 
the pouch thus formed, and the dog's head held until he swallows the 
dose. If the animal is refractory a cord thrown in two half-hitches 
oVer his nose will be of assistance in holding him. After the adminis- 
tration of the dose the dog should be tied short enough to prevent his 
lowering his head and getting rid of the medicine by vomiting. 

Preliminary treatment with a laxative not only serves to clear out the 
intestines so that the vermifuge will act more vigorously, })ut usuallv 
also expels fragments of tapeworms, from the number of which some 
idea of the degree of infection may be gained. An experienced 
observer will also be able to determine by stud}- of these fragments 
(tigs. 8, 9) the species of tapeworms to which they belong. Whether 
segments appear in the dog's feces or not, the practice of occasional 
vermifugal treatment should not be neglected. To render more cer- 
tain the expulsion of all tapeworms the treatment may be repeated in 
two weeks or a month. 

The following notes on vermifuges and their administration are taken 
from Stiles (1898): 

In selecting a remedy it is well to consider the following drugs. The doses (apothe- 
caries' weight) here given and the remarks on the drugs are abstracted from Frendi 
(1896). 

The doses of pelletierine tannate are, for adults, 5 to 15 grains; jjuj^pies, one-half 
to 5 grains. Pelletierine is undoubtedly the most efficient and innocuous ta?niaciile 
for the dog we possess, but is not much used on account of its expense. French has 
frequently found it most useful when the stomach has refused to retain other reme- 
dies. It should be administered in gelatin-capsular form in conjunction with pow- 
dered purgatives. 

Aspidium is perhaps the most reliable of all the vermifuges with the exception of 
pelletierine. For everyday practice it is to be preferred to all other remedies when 
given in the form of oleoresin. Doses: For adults, 15 to 40 minims; puppies, 5 to 15 
minims. The dose of the liquid extract is the same. 

Kamala is a very efficient ta^niacide with drastic purgative properties. Given in 
small amount as an adjunct to other tn^niacides, particularly to the oleoresin of male 
fern, it will be found a very valua)>le remedy. Doses: Adults, 15 to .SO grains; pup- 
pies, 3 to 15 grains. 

Brayera (U. S. P.), Cusso (B. P.), yields kosin or koussin, to which it owes its 
ticniacidal properties. It is one of the best and safest t;cniacides, its action being 
directly toxic to the worm, but it is too expensive for ordinary practice. The infu- 
sion {Iiifusuin brayera', U. S. P.) and fluid extract {Extraduyn hrayene fluidum) are 
both too bulky and disagreeable for administration to dogs. Kosin may be given in 
capsules in doses — adults, 10 to 40 grains; puppies, 10 to 20 grains. The drug usually 
acts as its own cathartic, but it is better to employ some adjunct for this i>urpose. 

Powdered «reca }(«/, when freshly ground, is a very good remedy for tapeworm. 



22 BUREAU OF ANIMAL INDUSTRY. 

When old, it will generally be found inert; consequently, it is best always to pur- 
chase the nut and grind or grate on an ordinary nutmeg grater. It is still largely 
used by British veterinarians and is a favorite with some Americans, but it can not be 
regarded as being either as effectual or easy of administration as the two preceding 
drugs. Its effects on puppies are not unattended with danger, on account of its great 
astringency; but with due regard to subsequent purgation it is a perfectly safe 
reniedy. Mayhew's method of prescribing 1 to 2 grains to every pound weight of 
the dog is usually followed, but the smaller quantity will generally suffice, provided 
the powder is freshly ground. It may be conveniently given in gelatin capsules, 
accompanied or followed by a purgative. 

Turpentine is a powerful remedy against tajieworms, l)ut it is regarded as being 
somewhat dangerous from its liability to j)roduce strangury and renal inflammation. 
These effects are said to be less pronounced after large than after small doses, but 
large doses are more liable to cause gastric and enteric inflammations. It can hardly, 
therefore, rank with the best remedies. Administer in emulsion with white of an 
egg, mucilage, milk, or oil. Doses: Adults 10 to 15 minims; puppies, 3 to 10 minims. 

Doctor Hoskins has had very satisfactory results with this drug in puppies under 
6 months of age and has never noticed any gastric or renal results. In very young 
puppies he rarely gives over 2 minims, carrying it up to 10 minims and repeating for 
two or three days on an empty stomach in the morning, allowing no food for an 
hour or two after its administration. 

The following- .sug-gestions as to doses, compiled from various sources, 
are taken from Curtice (1S90): 

(1) Allow 2 grains of freshly powdered areca nut for each pound of the dog's 
weight; administer dose in soup or milk, stirring it well, or by mixing it in butter 
or molasses. Follow in two hours with a tablespoonful of castor oil for a moderate- 
sized dog, giving the oil alone or in three times its quantity of milk. 

Ziirn advises 4 drams of areca nut for a large d(ig, 2h drams for a medium-sized 
animal, and 1 dram for a small dog." 

(2) One teaspoonful of turpentine and two tablespoonfuls of cast(jr oil given in a 
cup of milk. The flnal dose of physic is not given in this case. 

(3) Twenty drops of oil of male shield-fern, 30 drops of turpentine, and 60 drops 
of ether. Beat together with one egg and give to the dog in soup. 

(4) Hagen advises 80 grains of oxide of copper with 40 grains each of powdered 
chalk and Armenian bolus. Mix with sufficient water to make an adherent mass 
and divide into 100 pills. Administer one pill three times daily for ten days, in meat 
or butter. 

(5) Roll prescribes the following dose for large dogs; smaller doses should be given 
in proportion to the size of the dog: 

{<() Two drams each of extract of male fern and of powdered male fern; or 

(b) Decoction of 2^ ounces of pomegranate-root bark in water, reduced to 6 fluid 
ounces, to which add 1 dram of extract of male fern. Give in two doses, at intervals 
of one hour; or 

(c) One-half to 1 ounce of kousso, made into pills, with honey or molasses and a 
little meal; or 

(f?) From li ti) 2-2 drams of kamala, stirred with honey or water, and given in two 
doses inside of an hour. 

[«, b, and c should be followed in two hours with castor oil, but this is not neces- 
sary for d.] 

" The doses given by Ziirn are two to three times larger than those prescribed by 
American authorities iov freshly powdered areca nut, and should be used cautiously. 



THE (ilD PARASITE IN AMERICAN SHEEP. 23 

In jidclition to treating dog-s with vermifuges to rid tliem of the 
gid tapeworm, and tim.s removing the source from wdiich .sheep and 
cattle become infested, it is also essential that precautions be taken in 
turn to prevent the dogs from acquiring the parasite. This is accom- 
})lished h}^ preventing dogs from eating those portions of the carcasses 
of '"giddy" animals — namely, the brain and spinal cord — in which the 
bladderworm is located. These poi-tions should be destroyed by burn- 
ing, or rendered, or they may be thoroughly boiled, and can then be 
fed with safety to the dogs. 

Not onl}' is it a matter of immediate economy to slaughter animals 
affected with gid as soon as the symptoms indicating the final stage of 
the disease appear, and while they are still in good flesh, but it is also 
advisable from the prophylactic standpoint in that it removes a source 
of infestation to the dogs, and thus indirectly protects sheep and cattle 
f roiii infestation, provided, of course, that the heads of the slaughtered 
animals are properl}' disposed of as suggested above. 

O 



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